diff -r 3b578a5976df -r 64adf683bc7b src/jdk.jpackage/share/classes/jdk/jpackage/internal/AbstractAppImageBuilder.java
--- a/src/jdk.jpackage/share/classes/jdk/jpackage/internal/AbstractAppImageBuilder.java	Thu Oct 17 08:00:37 2019 -0400
+++ b/src/jdk.jpackage/share/classes/jdk/jpackage/internal/AbstractAppImageBuilder.java	Fri Oct 18 11:00:57 2019 -0400
@@ -116,7 +116,8 @@
                     mainJarType == ModFile.ModType.ModularJar)) {
                 out.println("app.mainmodule=" + mainModule);
             } else {
-                String mainClass = JLinkBundlerHelper.getMainClass(params);
+                String mainClass =
+                        StandardBundlerParam.MAIN_CLASS.fetchFrom(params);
                 // If the app is contained in an unnamed jar then launch it the
                 // legacy way and the main class string must be
                 // of the format com/foo/Main